Magnetic core structure

Abstract

Magnetic core structure of the stacked type having outer legs, an inner leg, and top and bottom yokes formed of a plurality of stacked groups of layers of metallic laminations. The length dimensions of the leg and yoke laminations are varied in opposite directions from layer to layer within each group of layers, while maintaining the midpoints of the laminations in each leg and yoke portion in alignment. This arrangement offsets the ends of the leg and yoke laminations from layer to layer and provides a stepped lap joint between adjoining ends of the leg and yoke laminations. The relative locations of the leg and yoke laminations are selected to uniformly divide the voids formed at the inner corners of the magnetic core between the leg and yoke laminations within each group of layers of laminations.

What is claimed is: 
     
       1. A magnetic core comprising: a plurality of stacked groups of layers of metallic laminations, each of said groups including a plurality of said layers;   each of said layers including first and second outer leg laminations and an inner leg lamination, each having first and second ends, and first and second yoke laminations forming a magnetic core having said outer and inner leg laminations connected by said yoke laminations and a plurality of outer and associated inner corners;   said yoke and said leg laminations having their ends cut diagonally to provide a closed magnetic circuit having diagonal joints between adjoining ends of said yoke and leg laminations;   the length dimensions of said outer and inner leg laminations and said first and second yoke laminations progressively varying in opposite directions from layer to layer within each group, while the respective midpoints of each leg and yoke lamination are aligned to offset said diagonally cut ends of said leg and yoke laminations from layer to layer in a stepped pattern that progresses at least three steps in one direction;   the relative locations of said leg and yoke laminations in the direction of their diagonal cut ends being selected to divide the voids formed at said inner corners of said magnetic core by the intersection of said leg and yoke laminations uniformly between said leg and yoke laminations in each group of layers of laminations.   
     
     
       2. The magnetic core of claim 1 wherein each layer of at least one of the first and second yoke portions is formed of first and second members disposed in butting relationship, with the length dimensions of each of said first and second members progressively varying from layer to layer, while the midpoints are aligned, to offset the ends of said first and second members from layer to layer to form a predetermined stepped pattern which progresses at least three steps.